I know that conceptually different diameter / tread depth is not advised for 4wd / awd vehicles - damage to things like the transfer case / center diff may occur. I'm not clear on what level of sensitivity there is though - like how different can a tire be before there is concern?

But applying this to a vehicle with electronic rather than mechanical 4wd/awd (ie - a new Camry AWD where the rear wheels have EV torque applied rather then through a center diff and axle), is this still true? And if so, what is the tolerance / sensitivity to tread depth differences between right/left rear or rear vs front? Any ideas?

Is this a practical concern and potential pain in the ass? Or is it basically no issue as long as the wheels are rotated (front to back?) every 5K miles or so?

False slip detection (traction control). Would cause issues, in snow. Brakes may also get applied when not needed. They come from the factory with the same size tires, don't overthink it.

I think it depends on the vehicle. My 2005 AWD Touareg (same as a Cayenne that model year) it was a problem when I had to replace 1 tire I had to replace 2 on the rear. I then discovered that the front tires (same model tires were about half worn) caused a jerk every few seconds until I replaced the front also.

I'd check your owners manual, some companies specify it.

I think the general consensus is +- 2/32" for AWD.

Part time 4WD doesn't care, you typically aren't supposed to use it on surfaces with good traction so there's enough slip that you don't get binding/ scrubbing.

Regular rotation should keep you well within spec, the only time you should run into trouble is if you need to replace a tire early.

For my AWD truck, I rotate every 5K miles.

For FWD, I should rotate since the fronts wear more quickly than the rears (not just tread depth but outer vs inner treads) but do so only rarely. This is my concern if I get the new AWD Camry - the fronts will likely get more worn than the rears. Sounds like this may be an issue even though electronic AWD so I need to rotate regularly. Kind of a pain but I can deal with it if AWD brings noticeable benefits.

For RWD, I rotate rarely but the tires wear pretty evenly.

I guess I need to consider more deeply whether I really should get the camry with awd vs fwd. Additional cost plus bother (regular rotation and pressure). Regardless, I should probably just do the rotations anyway especially since I have more time w/ retirement.

I should probably buy a tread depth gauge as well. I can't eyeball 2/32"

AWD is spectacularly great on snow. A good modern ABS and traction control will complement AWD in snow. Here in ski country the favorites by far are Audi Quattro and Subaru.

If you're on normal dry or wet pavement driving normally, AWD won't buy you anything.

It doesn't matter if it's AWD or FWD, the wheel speed sensors are affected by different tire diameter.

From AI:

Yes, both the front-wheel-drive (FWD) and all-wheel-drive (AWD) versions of the 2026 Toyota Camry use individual wheel speed sensors to manage traction control and the anti-lock braking system (ABS).

How Wheel Speed Sensors Work on the 2026 Camry

• Front Wheel Drive (FWD): Equipped with front and rear ABS wheel speed sensors that monitor rotational speed differences to detect wheel slip and activate traction control or stability control.
• All Wheel Drive (AWD): Uses an Electronic On-Demand AWD system that continuously tracks individual wheel speeds (along with throttle input) to detect when the front wheels lose grip.
• Sensor Hardware: Both configurations use dedicated wheel speed sensors at the wheels (such as OEM part numbers 89543AQ010 for the front-left and 8954406130 for the rear on AWD models) to feed real-time data to the skid control and traction computer.

I've always heard that the tires circumstances should be less than 1% difference on awd.
I was told by BMW to be within 0.8%.

For your car? Email toyota and ask.

.1

You can never measure tire circumference with sufficient accuracy to detect your concern.

Just buy the car you want, and follow a good tire rotation schedule. Don't worry about potential damage. You are not one to let that happen.

Cross rotation or just front-to-back will be specified by the engineers. Do what they say.

^^^
Bingo! For 99% of vehicles on the road this is the correct answer.

quote:

I think it depends on the vehicle.

Mainly, whether it has true AWD (all wheels powered all the time) vs. part-time, where only two wheels are powered unless selected manually or automatically. The former can be fussy about this, the latter a little less so. Limited-slip differentials also don't like differences in tire circumferences.